Phamaceutical/cosmetic compositions comprising hyaluronic acid and treatment of dermatological conditions therewith

ABSTRACT

Pharmaceutical/cosmetic compositions containing a dermatologically effective amount of hyaluronic acid, at least one retinoid and/or salt and/or derivative thereof, at least one oligosaccharide and at least one inhibitor of hyaluronic acid degradation, formulated into a physiologically acceptable medium therefor, are useful for the treatment of wrinkles, fine lines, fibroblast depletions and scars.

CROSS-REFERENCE TO PRIORITY/PCT APPLICATIONS

This application claims priority under 35 U.S.C. § 119 of FR 0513055,filed Dec. 21, 2005, and is a national phase of PCT/FR 2006/051391,filed Dec. 19, 2006 and designating the United States (published in theFrench language on Jul. 5, 2007 as WO 2007/074288 A1; the title andabstract were also published in English), each hereby expresslyincorporated by reference in its entirety and each assigned to theassignee hereof.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

The present invention relates to preparations for topical and/orparenteral administration, comprising hyaluronic acid formulated into aphysiologically acceptable medium, to processes for the production ofsuch preparations, and to uses thereof as a medicament, suchpreparations being especially useful for the treatment of dermatologicalconditions and afflictions, in particular for the treatment of wrinkles,fine lines, fibroblast depletions and any scars.

2. Description of Background and/or Related and/or Prior Art

Skin aging is one of the most visible modifications of the process ofsenescence. In addition, the skin is exposed to many factors thataccelerate this physiological process. A distinction can be made fromtwo different types of skin aging. Firstly, intrinsic aging, that it iseasier to evaluate on areas which are not normally exposed to the sunand, secondly, extrinsic aging, brought about by the interaction ofenvironmental factors, in particular UV rays. These environmentalfactors have a much more marked effect on the parts of the body exposedto the sun, especially in individuals of light phototype. This is thenalso referred to as actinic aging. Other factors, such as dietaryhabits, smoking, excessive alcohol consumption, chronic diseases andendocrine gland dysfunctions, also contribute to this aging.

During intrinsic skin aging, the horny layer is relatively unmodified.The epidermis is atrophic and the dermal-epidermal junction isflattened, such that the adhesion to the dermis is weaker, facilitatingthe formation of bubbles. The thickness of the dermis is clearlyreduced; there are fewer blood vessels. Fewer fibroblasts are alsoobserved and their biosynthetic and proliferative capacities arereduced. The elastic fibers first undergo modifications, andsubsequently disappear.

As regards extrinsic aging, an irregular, sometimes atrophic, sometimeshyperplasic, epidermis is observed, with signs of disorganization and ofdysplasia. There are more melanocytes in certain areas, and fewer inothers. The distribution of melanin in the epidermis is also irregular,subsequent to melanosome transfer problems. The number of Langerhanscells decreases. The small blood vessels are first dilated, and thenbecome thinner and atrophy.

Wrinkles are the most visible signs of aging. A distinction can be madefrom several types, in particular superficial and deep wrinkles. Deepwrinkles are thought to be due to dermo-hypodermal modifications,whereas superficial wrinkles could be explained by dermal and possiblyepidermal modifications. Wrinkles are especially due to the loss ofelasticity of the skin. The effect on the subepidermal elastic networkgives rise to superficial laxity of the aged skin and folding of itssurface. The destruction of the elastic fibers in the reticular dermisis responsible for the loss of elasticity and of the skin's ability toreturn to its shape after stretching. A suitable treatment will bepossible according to the type, the intensity and the topography.

The treatment of unattractive skin modifications related to aging hasmade enormous progress over the past few years.

A relatively large number of natural or synthetic substances havealready been described as dermal implants, i.e., as substances injecteddirectly into the skin, in order to remedy skin alterations resultingfrom aging, traumas or diseases.

Other therapeutic alternatives for these applications are in particularthe local injection of botulinum toxin (Botox®) or the use of lasertechniques. These various types of treatment are not exclusive and acombination thereof has even been recommended. Among the naturalsubstances of human origin, collagen and hyaluronic acid are those whichform the basis of the majority of products available on the market.

Hyaluronic acid is a ubiquitous natural polysaccharide which exists inthe same form from the simplest bacterium to humans. It is a polymer ofdisaccharides which are themselves composed of D-glucuronic acid andN-acetylglucosamine, linked to one another by alternating beta-1,4 andbeta-1,3 glycosidic linkages. The polymers of this recurring unit may befrom 102 and 104 kDa in size, in vivo. Hyaluronic acid represents inparticular a natural constituent of the dermis, where it plays animportant role in the hydration and elasticity of the skin. However, itdecreases in amount and in quality with age, leading to drying out ofthe skin, which becomes wrinkled. It is highly water-soluble and formshigh-viscosity solutions in water. Because of these specific properties,hyaluronic acid is among the pharmaceutical products most commonly used.

However, in humans, hyaluronic acid is very rapidly eliminated from theplasma by degradation. Its plasma half-life after intravenous injectionis very short, from 2.5 to 5 minutes, whereas in the skin, its half-lifeis from 0.5 to 2 days depending on its concentration. Its excretion inthe urine is low, less than 1% of total clearance. In rabbits, the rateof elimination, in the skin, has been measured (Reed R K, Laurent U B,Fraser J R, Laurent T C. Removal rate of [3H]hyaluronan injectedsubcutaneously in rabbits, Am. J. Physiol., 1990 August; 259 (2 Pt 2):H532-5). It is non-exponential with a half-life of 0.5 to 1 day when itsconcentration is 5 mg/ml.

The tolerance of hyaluronic acid is very good and no immunogenicity hasbeen associated with this substance. A very low incidence of sideeffects is thus observed.

The use of hyaluronic acid, alone or in combination, has thus beendescribed for several medical applications, such as, for example, thetreatment of osteoarthritis and also rheumatoid arthritis. Injectablecompositions such as, for example, hyaluronic acid alone, collagen aloneor the combination of “hyaluronic acid and collagen” have also alreadybeen employed in repair surgery, in the context of the treatment byfilling of wrinkles, fine lines, fibroblast depletions and any scars.

Currently, many dermal implants are used but none has yet beenconsidered to be ideal in the context of a safe and healthy tissueaugmentation (Naoum C, Dasiou-Plakida D. Dermal filler materials andbotulin toxin, Int. J. Dermatol., 2001 October; 40(10): 609-21).

However, because the bioavailability of hyaluronic acid is too low afterinjection and its injection frequency is too high, it cannot be used assuch.

Of course, there has been an effort to develop compositions based onhyaluronic acid having a very good bioavailability and capable of moresuccessfully withstanding the action of degradation enzymes. This makesit possible, in particular, to space out the procedures and to reducethe number thereof.

These compositions employed as a dermal implant are all composed ofstabilized hyaluronic acid and a large number of these comprisehyaluronic acid that has been chemically modified for this purpose. Inaddition, the hyaluronic acid included in these products ispredominantly of nonhuman origin, for instance of avian or bacterialorigin.

Numerous chemically modified hyaluronic acid derivatives in the form, inparticular, of esters, amides and also derivatives having “intra- and/orinterchain bridges” (crosslinked), are thus found in these compositions.

However, these modifications affect the physicochemical characteristicsand the biological properties of hyaluronic acid, and also its outcomeafter administration. These structural modifications of hyaluronic acidcan lead to inflammatory reactions, as reported by Sopaar C N S,Patrinely J R Ophthalmic plastic and reconstructive surgery 2005 March;21(2): 151-53.

Furthermore, the bioavailability of these hyaluronic acid derivatives,although better than that of natural hyaluronic acid, still remains tooshort.

SUMMARY OF THE INVENTION

Novel preparations comprising hyaluronic acid have now been developedhaving a better bioavailability while at the same time conserving thephysicochemical characteristics and biological properties thereof, aswell as a process for the formulation of such preparations.

Thus, the present invention features pharmaceutical or cosmeticcompositions or preparations, in particular for topical and/orparenteral administration, comprising, formulated into a physiologicallyacceptable medium, hyaluronic acid, and also:

at least one retinoid and/or salts thereof and/or derivatives thereof,

at least one oligosaccharide, and

at least one inhibitor of hyaluronic acid degradation.

The present invention also features a process for the production of apharmaceutical or cosmetic composition or preparation for topical and/orparenteral application, comprising, in a physiologically acceptablemedium, hyaluronic acid, and at least one retinoid and/or salts thereofand/or derivatives thereof, at least one oligosaccharide and at leastone inhibitor of hyaluronic acid degradation, which comprises the stepof mixing an effective amount of hyaluronic acid with at least oneretinoid and/or salts thereof and/or derivatives thereof, at least oneoligosaccharide and at least one inhibitor of hyaluronic aciddegradation. Preferably, the process according to the invention alsocomprises a step of preparing a physiologically acceptable medium, inwhich the active agents are mixed.

Finally, this invention features administration of the subjectpreparations as medicaments for the treatment and/or prevention ofdermatological conditions/afflictions, whether comprising a regime orregimen.

When a pharmaceutical or cosmetic composition or preparation for topicaland/or parenteral application comprises, formulated into aphysiologically acceptable medium, hyaluronic acid, and at least oneretinoid and/or salts thereof and/or derivatives thereof, at least oneoligosaccharide and at least one inhibitor of hyaluronic aciddegradation, it clearly increases the bioavailability of the hyaluronicacid, it makes it possible to space out the applications and to reducethe number thereof and it is highly effective in filling wrinkles, finelines, fibroblast depletions and any scars.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be understood more clearly from the description tofollow and the attached Figures of Drawing, in which:

FIG. 1 shows, in a semilogarithmic representation, the results of astudy, the objective of which was to evaluate the inhibitory effect ofglycyrrhizin on hyaluronidase activity of bovine origin, and

FIG. 2 shows the results of a study, the objective of which was toevaluate the effect of the combination “GLZ+pentamer (NAG-glucuronicacid)5+retinol” on the neosynthesis of hyaluronic acid by normal humankeratinocytes.

DETAILED DESCRIPTION OF BEST MODE AND SPECIFIC/PREFERRED EMBODIMENTS OFTHE INVENTION

The preparations according to the invention comprise, formulated into aphysiologically acceptable medium, hyaluronic acid, and at least oneretinoid and/or salts thereof and/or derivatives thereof, at least oneoligosaccharide and at least one inhibitor of hyaluronic aciddegradation.

The present invention thus also features products comprising:

hyaluronic acid,

at least one retinoid and/or salts thereof and/or derivatives thereof,

at least one oligosaccharide, preferably one, and

at least one inhibitor of hyaluronic acid degradation, preferably one,as a combination product for simultaneous, separate or sequentialadministration in the treatment of dermatological conditions.

Such a combination product is in particular effective in the treatmentof wrinkles, fine lines, fibroblast depletions and scars.

The term “combination product” means a single composition comprisingeach of the active compounds, but also a complex composition comprisingat least two different compositions, each comprising a part of theactive agents of said preparation.

The term “active agents” means, according to the present invention, thecompounds selected from hyaluronic acid, at least one oligosaccharide,at least one inhibitor of hyaluronic acid degradation and at least oneretinoid and/or salts thereof and/or derivatives thereof. Thus, thecombination product according to the invention comprises at least 4active agents.

Exemplary combination products according to the invention include:

a single composition comprising hyaluronic acid, a retinoid and/or saltsthereof and/or derivatives thereof, an oligosaccharide and an inhibitorof hyaluronic acid degradation;

a composition comprising just one of these four active agents, combinedwith a composition comprising at least the other three active agents;

a composition comprising two of these four active agents, combined witha composition comprising at least the other two active agents; and

a composition comprising three of these four active agents, combinedwith a composition comprising at least the fourth active agent.

Preferably, the combination product according to the invention comprisesa composition A comprising hyaluronic acid in the form of an injectable(preferably aqueous) solution, combined with a composition B comprising:

at least one inhibitor of hyaluronic acid degradation, preferablyglycyrrhizin,

at least one oligosaccharide, preferably the pentamer (NAC-glucuronicacid)5, and

at least one retinoid and/or salts thereof and/or derivatives thereof,preferably retinol,

in the form of a composition for topical application.

The term “physiologically acceptable medium” means, according to theinvention, a medium compatible with the skin and, optionally, with itsappendages (eyelashes, nails, hair) and/or the mucous membranes.

In the preparations according to the invention, the hyaluronic acid, theretinoid and/or salts thereof and/or derivatives thereof, theoligosaccharide and the inhibitor of hyaluronic acid degradation arepresent in proportions that can range from 0.0000001% to 10%, preferablyfrom 0.00001% to 1% by weight, relative to the total weight of thepreparation. In the present description, and unless otherwise specified,it is understood that, when concentration ranges are given, they includethe upper and lower limits of said range.

The preparations according to the invention comprise hyaluronic acid.

The term “hyaluronic acid” means the compound constituted of the seriesof glucuronic acid and of N-acetylglucosamine.

Advantageously, the hyaluronic acid is natural.

The term “natural hyaluronic acid” means a hyaluronic acid that isnon-stabilized and non-chemically modified in the form, in particular,of esters or amides or in the form of derivatives having “intra- and/orinterchain bridges” (crosslinked), such modifications affecting thephysicochemical characteristics and the biological properties of saidhyaluronic acid, and also what becomes of it after administration.

The preparations according to the invention also comprise a retinoidand/or salts thereof and/or derivatives thereof, taken alone or as amixture.

Among the retinoids that may be part of the preparations according tothe invention, retinol, retinal and/or retinoic acid, and salts andderivatives thereof, taken alone or as a mixture, will preferably beselected, more preferably retinol.

The term “retinoid salt” means, in particular, an alkali metal salt, analkaline-earth metal salt or an organic amine salt. The term “retinoidderivative” means in particular the esters, such as retinyl palmitate,retinyl acetate, retinyl stearate, retinyl oleate, retinyl propionate orelse retinyl linoleate.

Advantageously, the retinoids included in the preparations according tothe invention are retinoids that exist naturally in the human body.

The preparations according to the invention also comprise anoligosaccharide.

The term “oligosaccharide” means, in particular, any oligosaccharidewhich limits the penetration of hyaluronic acid into the cells of theskin, in particular the keratinocytes and the fibroblasts.

Among the oligosaccharides, taken alone or as a mixture, that may bepart of the preparations according to the invention, hyaluronic acidoligomers, preferably hyaluronic acid trimers to decamers, morepreferably hyaluronic acid tetramers to hexamers, more preferentiallythe hyaluronic acid pentamer, will be selected.

Advantageously, the oligosaccharides used in the preparations accordingto the invention are compounds that exist naturally in the human body.

In the preparations according to the invention, the oligosaccharide isused at concentrations of from 10⁻⁹ M and 10 ⁻³ M, preferably from 10⁻⁸M and 10 ⁻⁵ M.

The preparations according to the invention also comprise an inhibitorof hyaluronic acid degradation.

The term “inhibitor of hyaluronic acid degradation” means a compoundcapable of reducing, or even blocking, either the extracellular or theintracellular catabolism of hyaluronic acid, preferably a compoundcapable of reducing, or even blocking, the extracellular catabolism ofhyaluronic acid, more preferably a compound capable of inhibiting theextracellular hyaluronidase present in the skin.

Among the inhibitors of hyaluronic acid degradation, taken alone or as amixture, that may be included in the preparations according to theinvention, glycyrrhizin or glycyrrhetinic acid, and derivatives and/oranalogs thereof, will in particular be selected.

Advantageously, the inhibitors of hyaluronic acid degradation includedin the preparations according to the invention are natural.

In the preparations according to the invention, the inhibitor is presentat concentrations of from 10⁻⁹ M and 10 ⁻² M, preferably from 10⁻⁶ M and10 ⁻³ M.

The term “derivatives of glycyrrhizin or of glycyrrhetinic acid” means,in particular, the salts, the substituted derivatives, the enantiomersand the racemates of said compounds.

As salts of said compounds, exemplary are the salts obtained by additionof said compounds with an inorganic base, selected in particular fromamong sodium hydroxide, lithium hydroxide, calcium hydroxide, potassiumhydroxide, magnesium hydroxide, ammonium hydroxide or zinc hydroxide,and alkali metal or alkaline-earth metal carbonates such as sodium,lithium, calcium, potassium, magnesium, ammonium or zinc carbonates andbicarbonates, or with an organic base, selected, in particular, fromamong methylamine, propylamine, trimethylamine, diethylamine,triethylamine, N,N-dimethylethanolamine,tris(hydroxymethyl)aminomethane, ethanolamine, pyridine, picoline,dicyclohexylamine, morpholine, procaine, lysine, arginine, histidine,N-methylglucamine or else phosphonium salts such as alkylphosphoniumsalts, arylphosphonium salts, alkylarylphosphonium salts,alkenylarylphosphoniums or quaternary ammonium salts such astetra-n-butylammonium salts. Such salts are in particular the potassiumsalt of glycyrrhetinic acid, the sodium salt of glycyrrhetinic acid, orelse the monoammonium salt of glycyrrhetinic acid (ammoniumglycyrrhetinate).

The term “analog” means, in particular, the enzymatic or biomimeticanalogs of said compounds, capable of binding to the catalytic ornoncatalytic site of hyaluronidases and of thus inhibiting theiractivation. Such analogs may be selected, in vitro, by means ofhyaluronidase binding or inhibition assays according to the techniquesconventionally used.

Advantageously, the derivatives and/or analogs should be of naturalorigin.

The compounds and derivatives and/or analogs thereof of natural originare compounds in the pure state or in solution at variousconcentrations, obtained by various methods for extracting orhydrolyzing biological material of natural origin.

In a known manner, the preparations according to the invention may alsocontain the usual adjuvants known to those skilled in the art.

The preparations according to the invention are formulated for topicaland/or parenteral application.

When they are for topical application, the preparations may be in any ofthe galenical forms normally employed for topical administration.Exemplary topical preparations include preparations in liquid, pasty orsolid form, and more particularly in the form of ointments, aqueous,aqueous-alcoholic or oily solutions, dispersions of the optionallytwo-phase lotion type, serum, aqueous, anhydrous or lipophilic gels,powders, impregnated pads, syndets, wipes, sprays, foams, sticks,shampoos, compresses, washing bases, emulsions of liquid or semi-liquidconsistency of the milk type, obtained by dispersion of a fatty phase inan aqueous phase (O/W) or vice versa (W/O), a microemulsion, suspensionsor emulsions of soft, semi-liquid or solid consistency of the white orcolored cream, gel or ointment type, suspensions of microspheres ornanospheres or lipid or polymeric vesicles, or microcapsules,microparticles or nanoparticles or polymeric or gelled patches forcontrolled release.

When they are for parenteral administration, the preparations accordingto the invention may be administered subcutaneously or intradermally.Exemplary parenteral preparations include preparations in the form ofsolutions or suspensions for perfusion or for injection.

According to the invention, the compounds constituting the preparationmay be administered according to the same method of administration oraccording to a combined method of administration.

The term “combined method of administration” means the administration ofone or more compound(s) of the preparation according to the invention bytopical administration combined with a parenteral administration, inparticular by subcutaneous or intradermal injection of the othercompound(s) of the preparation.

Advantageously, one fraction of the compounds is first applied topicallyand another fraction of said compounds is then applied parenterally, orvice versa.

According to an alternative embodiment of the invention, it is alsopossible to simultaneously apply one fraction of the compounds topicallyand another fraction of said compounds parenterally.

Indeed, the hyaluronic acid may even be administered in the form of aninjectable aqueous solution, the retinol, the hyaluronic acid pentamerand the glycyrrhizin being administered in the form of a cream.

In the context of a combined administration, the administrationfrequencies may be identical or different.

As one example, the frequency of administration of hyaluronic acidinjected in the form of an injectable aqueous solution may range from 1to 12 months, preferably from 6 to 12 months, whereas those of the othercompounds of the preparation according to the invention, administered inthe form of a cream, may range from 1 to 7 days, preferably from 1 to 3days.

The process for the production a preparation according to the inventioncomprises a step of mixing an effective amount of hyaluronic acid, atleast one retinoid and/or salts thereof and/or derivatives thereof, atleast one oligosaccharide and at least one inhibitor of hyaluronic aciddegradation. Preferably, said process comprises a step of preparing aphysiologically acceptable medium, to which the active agents are added.

According to a specific embodiment of the invention, the process for theproduction of a preparation comprises the steps of preparing aphysiologically acceptable medium and of mixing an effective amount ofhyaluronic acid, retinol, hyaluronic acid pentamer, and glycyrrhizinand/or derivatives thereof and/or analogs thereof.

Advantageously, the process for the production of a combination productaccording to the invention comprises a first step of preparing aninjectable solution, comprising mixing the hyaluronic acid with aphysiologically acceptable medium, and a second step of preparing aformulation suitable for topical administration, comprising mixing atleast one retinoid and/or salts thereof and/or derivatives thereof, withat least one oligosaccharide and at least one inhibitor of hyaluronicacid degradation in a physiologically acceptable medium.

The present invention also features administration of a preparation asdescribed above as a medicament useful in the treatment and/orprevention of dermatological conditions/afflictions.

More particularly, this invention features administration of apreparation as described above as a medicament useful in the treatmentof wrinkles, fine lines, fibroblast depletions and scars. Such amedicament is suitable for the treatment of wrinkled and/or aged skin,and is useful, in particular, to prevent and/or reduce the effectsthereof. The treatment of wrinkles, fine lines, fibroblast depletionsand any scars is carried out in particular by filling.

In particular, the preparations according to the invention may beapplied to the areas of the face or of the forehead that are marked withexpression wrinkles.

The present invention also features administration of a preparation asdescribed above as a medicament useful in repair surgery.

In addition, this invention features such preparations within a dermalimplant.

In order to further illustrate the present invention and the advantagesthereof, the following specific examples are given, it being understoodthat same are intended only as illustrative and in nowise limitative. Insaid examples to follow, all parts and percentages are given by weight,unless otherwise indicated.

Example 1 Inhibitory Effect of Glycyrrhizin (GLZ) on HyaluronidaseActivity of Bovine Origin

Determination of the IC₅₀ of GLZ, with or without Pre-Incubation at 37°C.:

GLZ, at various concentrations, is or is not pre-incubated for 20minutes at 37° C. in the presence of the enzyme. The enzyme reaction istriggered by adding the hyaluronic acid solution (time T0). Afterincubation for 20 minutes, the non-hydrolyzed hyaluronic acid isprecipitated by adding acidic bovine albumin solution.

In order to verify that the pre-incubation step has no effect on thestability of the hyaluronidase, an aliquot of a solution of the enzymeis placed at 37° C. for 20 minutes. Another aliquot is conserved in anice bath for 19 minutes, and is then incubated at 37° C. for 1 minute. Asolution of hyaluronic acid is then added to each aliquot (T0). Afterincubation for 15, or 45 minutes, the non-hydrolyzed hyaluronic acid isprecipitated by addition of acidic bovine albumin solution.

Measurement of the Hyaluronidase Activity of Bovine Origin:

After the precipitation step, the turbidimetry of the solutions isdetermined on a spectrophotometer at a wavelength of 600 nm. The opticaldensity (OD) of these solutions is subtracted from the OD of a controlsolution of hyaluronic acid (of the same concentration) not hydrolyzedby the enzyme. This difference in OD, which is inversely proportional tothe concentration of hyaluronic acid, is used to measure the activity ofthe hyaluronidase.

The inhibitory effect of GLZ on the bovine hyaluronidase is shown inFIG. 1 (semilogarithmic representation).

The results obtained show that this effect is dose-dependent and thatthe concentration of GLZ which gives 50% inhibition (IC₅₀) of thehyaluronidase activity is 400 μM without pre-incubation with the enzyme.

When the GLZ is pre-incubated for 20 minutes at 37° C. in the presenceof the enzyme, the IC₅₀ is 350 μM.

Example 2 Inhibitory Effect of the “GLZ+Pentamer (NAG-GlucuronicAcid)5+Retinol” Combination on the Neosynthesis of Hyaluronic Acid byNormal Human Keratinocytes

According to the prior art, it is accepted that an equilibriumpre-exists from the neosynthesis and the degradation of hyaluronic acid.In other words, the neosynthesis of hyaluronic acid is a reflection ofits degradation: measuring the variations in one therefore amounts tomeasuring the variations in the other. For reasons of technicalsimplicity, the change in neosynthesis of hyaluronic acid in thepresence of the “GLZ+pentamer (NAG-glucuronic acid)5+retinol”combination is measured, relative to the corresponding control.

The adult human keratinocytes (NHK) are isolated from a fragment ofhuman skin collected after an abdominoplasty operation (subject CAOL, 38years old).

The NHK are cultured to confluence as a monolayer in 24-well plates andsub-cultured. The NHK are used following the third passage.

The culture medium used is MCK medium at 37° C. in a humid atmospherecontaining 5% CO₂.

The MCK culture medium is an SFM defined keratinocyte medium comprisinggrowth factors, to which penicillin (50 IU/ml) and streptomycin (50μg/ml) are added.

Preparation of Reagents:

The pentamer (NAG-glucuronic acid)5 is dissolved at 2 mg/ml in the MIKculture medium (MCK medium containing 2 μCi/ml of radiolabeledglucosamine). It is then diluted in an MIK medium containing 0.2% DMSO.

This product is tested at 0.1-0.5 and 2 mg/ml.

The glycyrrhizin (GLZ) is dissolved at 400 mM in DMSO. It is thendiluted in the MIK culture medium (MCK medium containing 2 μCi/ml ofradiolabeled glucosamine).

This product is tested at 100-400 and 800 μM (concentration of DMSO keptconstant: 0.2%).

The retinol is dissolved at 10 mM in DMSO. It is then diluted in the MIKculture medium (MCK medium containing 2 μCi/ml of radiolabeledglucosamine).

This product is tested at 1-10 and 100 nM (concentration of DMSOmaintained constant: 0.2%).

The “GLZ+pentamer (NAG-glucuronic acid)5+retinol” combination isprepared by mixing the stock solutions prepared above. It is thendiluted in MIK medium (MCK medium containing 2 μCi/ml of radiolabeledglucosamine).

This product is tested at:

100 μM GLZ+0.1 mg/ml pentamer (NAG-glucuronic acid)5+1 nM retinol;

400 μM GLZ+0.5 mg/ml pentamer (NAG-glucuronic acid)5+10 nM retinol;

800 μM GLZ+2 mg/ml pentamer (NAG-glucuronic acid)5+100 nM retinol.

These three solutions have a constant DMSO concentration of 0.2%.

Experimental protocol: (Pienimaki et al., The Journal of BiologicalChemistry, (2001) Vol. 276, No. 23, June 8, p20428-20435).

The reaction system is constituted of normal human keratinocytes as amonolayer culture in 24-well plates (cells at confluence at thebeginning of the incubation).

The NHK are incubated in the presence of the test products and ofradiolabeled glucosamine for 6-12-24 and 48 hours, in a final volume of400 μl of medium per culture well. The incubation temperature is 37° C.,the humid atmosphere contains 5% CO₂.

a. Recovery of all the Gags Comprising Radiolabeled Glucosamine:

At the end of the incubation, the culture media are recovered bycentrifugation and then the cell layers are rinsed with PBS. The mixturecomposed of the rinsing medium and of the initial supernatant isrecovered. After the addition of hyaluronic acid (10 μg/fraction, roleof “carrier” during the precipitations with cetyl pyridinium chloride(CPC)) and of papain (200 μg/fraction, hydrolysis of proteoglycans withrelease of GAGs), the fractions are incubated for 2 hours at 60° C., andthen the fractions are incubated for 10 minutes at 100° C. in order toinactivate the enzymes by heat denaturation. Finally, the GAGs areprecipitated by the addition of CPC (final concentration of 1%) andincubated overnight at ambient temperature. After centrifugation for 10minutes at 15 000 g, and then elimination of the supernatants containingthe non-incorporated radiolabeled glucosamine, the pellets are rinsedwith 1% CPC, and a further centrifugation of 10 minutes at 15 000 g iscarried out, followed by elimination of the supernatants.

b. Measurement of Hyaluronic Acid Neosynthesis:

The hyaluronic acid contained in the centrifugation pellets isspecifically hydrolyzed by incubation (3 hours at 37° C.) of thesepellets with hyaluronidase (hyaluronan lyase from Streptomyceshyalurolyticus, 0.25 unit/fraction). For this, the medium containingthese pellets and the hyaluronidase are incubated for 3 hours at ambienttemperature, followed by centrifugation for 10 minutes at 15 000 g.Finally, the non-hydrolyzed GAGs are precipitated by adding CPC (1%final concentration) in the presence of chondroitin sulfate (50μg/fraction—role of “carrier”). The radioactivity of the supernatant,determined by liquid scintillation (β-counter), is directly proportionalto the amount of hyaluronic acid neosynthesized during the incubation ofthe cells with the radiolabeled glucosamine.

The radioactivity measurements are given in the following tables:

TABLE 1 Measurement of hyaluronic acid neosynthesis by normal humankeratinocytes in the absence of the “GLZ + pentamer (NAG-glucuronicacid)5 + retinol” combination (control). Incubation IncubationIncubation Incubation Incubation 6 h 12 h 24 h 48 h 72 h dpm 4156 12 21638 404 62 938 64 701 3997 11 874 34 050 70 271 74 910 4232 12 463 30 26462 411 79 646 Mean 4128 12 184 34 239 65 207 73 086 Standard  120   296  4073   4394   7638 deviation

TABLE 2 Measurement of hyaluronic acid neosynthesis by normal humankeratinocytes in the presence of the “GLZ + pentamer (NAG-glucuronicacid)5 + retinol” combination. Incubation Incubation IncubationIncubation Incubation 6 h 12 h 24 h 48 h 72 h 100 μM GLZ + 0.1 mg/mlpentamer (NAG-glucuronic acid)5 + 1 nM retinol dpm 3508 12 844 28 289 51974 63 822 3388 14 053 26 971 55 088 64 251 3697 13 347 30 200 56 652 61504 Mean 3531 13 415  28 487**  54 571**  63 192** Standard 156   607  1624   2381   1478 deviation 400 μM GLZ + 0.5 mg/ml pentamer(NAG-glucuronic acid)5 + 10 nM retinol dpm 3672   9847 25 363 26 813 54202 3698 10 724 27 404 36 235 49 799 3461 10 577 25 351 29 007 54 488Mean 3610   10 383***   26 039***   30 685***   52 830*** Standard 130  470   1182   4930   2629 deviation 800 μM GLZ + 2 mg/ml pentamer(NAG-glucuronic acid)5 + 100 nM retinol dpm 3203   8263 17 640 32 714 33910 3401   8875 19 682 30 070 29 693 2580   7590 21 320 29 092 29 194Mean 3061    8243***   19 547***   30 625***   30 932*** Standard 428  643   1844   1874   2591 deviation **mean significantly different thanthat of the control group (p < 0.05) ***mean significantly differentthan that of the control group (p < 0.01)

The inhibitory effect of the “GLZ+pentamer (NAG-glucuronicacid)5+retinol” combination on the hyaluronic acid neosynthesis bynormal human keratinocytes is shown in FIG. 2.

The results obtained show a marked inhibition of hyaluronic acidneosynthesis. This effect is dose-dependent and, at the highestconcentrations of the three components, the inhibition of neosynthesisis of the order of 50% to 60%. Owing to the pre-existing equilibriumfrom neosynthesis and degradation of hyaluronic acid, this observedinhibition of neosynthesis corresponds to an equivalent inhibition ofdegradation.

One may therefore conclude that the effect of the combination protectshyaluronic acid against degradation. This system therefore makes itpossible to increase the biostability of hyaluronic acid and,consequently, to improve its bioavailability.

Example 3 Composition No. 1

Injectable solution No. 1 containing the 4 components:

This composition is prepared in a manner that is conventional for thoseskilled in the art:

Hyaluronic acid 2% Glycyrrhizin 0.02% Pentamer (NAC-glucuronic acid)50.002% Retinol 0.00001% Water qs 100%

Example 4 Composition No. 2

Injectable solution No. 2 containing hyaluronic acid, coupled with acream containing the other 3 components:

Injectable Solution:

Hyaluronic acid 2% Water qs 100%

Cream:

Glycyrrhizin 0.02% Pentamer (NAC-glucuronic acid)5 0.002% Retinol0.00001% Stearic acid 3.00% Mixture of glyceryl monostearate 2.5% andPEG stearate (100 EO) PEG stearate (20 EO) 1.0%Cyclopentadimethylsiloxane 10.00% Plant oils 7.00% Synthetic oils 6.00%Silicone gum 0.20% Stearyl alcohol 1.00% Water qs 100%

Each patent, patent application, publication, text and literaturearticle/report cited or indicated herein is hereby expresslyincorporated by reference in its entirety.

While the invention has been described in terms of various specific andpreferred embodiments, the skilled artisan will appreciate that variousmodifications, substitutions, omissions, and changes may be made withoutdeparting from the spirit thereof. Accordingly, it is intended that thescope of the present invention be limited solely by the scope of thefollowing claims, including equivalents thereof.

1. A pharmaceutical/cosmetic composition which comprises adermatologically effective amount of hyaluronic acid, at least oneretinoid and/or salt and/or derivative thereof, at least oneoligosaccharide and at least one inhibitor of hyaluronic aciddegradation, formulated into a physiologically acceptable mediumtherefor.
 2. The pharmaceutical/cosmetic composition as defined by claim1, said at least one retinoid and/or salt and/or derivative thereofcomprising retinol.
 3. The pharmaceutical/cosmetic composition asdefined by claim 1, said at least one oligosaccharide comprising ahyaluronic acid oligomer.
 4. The pharmaceutical/cosmetic composition asdefined by claim 1, said at least one inhibitor of hyaluronic aciddegradation comprising glycyrrhizin or glycyrrhetinic acid, and/orderivative and/or analog thereof.
 5. The pharmaceutical/cosmeticcomposition as defined by claim 1, formulated for topical application.6. The pharmaceutical/cosmetic composition as defined by claim 1,formulated for parenteral administration.
 7. The parenteral formulationas defined by claim 6, comprising a solution or suspension for perfusionor for injection.
 8. The pharmaceutical/cosmetic composition as definedby claim 1, formulated as a combination product for simultaneous,separate or sequential administration in the treatment of dermatologicalconditions/afflictions.
 9. The combination product as defined by claim8, comprising a fraction A which comprises hyaluronic acid in the formof an injectable solution, and a fraction B which comprises at least oneinhibitor of hyaluronic acid degradation, at least one oligosaccharide,and at least one retinoid and/or salt and/or derivative thereof,formulated for topical application.
 10. A process for the production ofa pharmaceutical/cosmetic composition as defined by claim 1, comprisingmixing an effective amount of hyaluronic acid, at least one retinoidand/or salt and/or derivative thereof, at least one oligosaccharide andat least one inhibitor of hyaluronic acid degradation, and formulatingsame into a physiologically acceptable medium therefor.
 11. A processfor the production of a combination product as defined by claim 9,comprising: a first step of preparing an injectable solution, whichcomprises mixing the hyaluronic acid with a physiologically acceptablemedium, and a second step of formulating a composition suitable fortopical administration, comprising mixing at least one retinoid and/orsalt and/or derivative thereof with at least one oligosaccharide and atleast one inhibitor of hyaluronic acid degradation in a physiologicallyacceptable medium therefor.
 12. A regime or regimen for the treatmentand/or prevention of a dermatological condition or affliction,comprising administering to an individual in need of such treatment, adermatologically effective amount of hyaluronic acid, at least oneretinoid and/or salt and/or derivative thereof, at least oneoligosaccharide and at least one inhibitor of hyaluronic aciddegradation.
 13. A regime or regimen for conducting repair surgery on anindividual in need of such treatment, comprising, before or during suchrepair surgery, administering to said individual a thus effective amountof hyaluronic acid, at least one retinoid and/or salt and/or derivativethereof, at least one oligosaccharide and at least one inhibitor ofhyaluronic acid degradation.
 14. A regime or regimen for the treatmentof wrinkles, fine lines, fibroblast depletions or scars afflicting anindividual's skin, comprising filling same with a thus effective amountof hyaluronic acid, at least one retinoid and/or salt and/or derivativethereof, at least one oligosaccharide and at least one inhibitor ofhyaluronic acid degradation.
 15. A dermal implant comprising hyaluronicacid, at least one retinoid and/or salt and/or derivative thereof, atleast one oligosaccharide and at least one inhibitor of hyaluronic aciddegradation.